| Ssflco Ltd | Hospitality | 2026 |
| Stab Properties Management Company Limited | Households | 2002 |
| Station Road (Dunloy) Management Company Ltd | Extraterritorial | 2023 |
| Station Road Management Company (Castledawson) Ltd | Extraterritorial | 2007 |
| Statura Services Ltd | Professional & scientific | 2025 |
| Stendhal Festival Ltd | Arts & recreation | 2013 |
| Steph's Kitchen Design Ltd | Professional & scientific | 2025 |
| Strand Asset Management Limited | Construction | 2015 |
| Strathearn Construction Ltd | Construction | 2011 |
| Strule Consultancy Ltd | Professional & scientific | 2011 |
| Suiram Ltd | Construction | 2012 |
| Sunrise Superfoods Ltd | Hospitality | 2025 |
| Swallow Court Management Company (Ballymoney) Limited | Households | 2005 |
| Swaraj Ltd | Professional & scientific | 2001 |
| Swellbeing NI Limited | Other services | 2023 |
| Tamnadeese Asset Management Ltd | Construction | 2015 |
| Tangible Properties Limited | Real estate | 2007 |
| Tank and Skinnys Ltd | Hospitality | 2020 |
| Taste Causeway Community Interest Company | Other services | 2019 |
| TB Asset Management Limited | Financial services | 2024 |
| TC Fulfillment Ltd | Wholesale & retail | 2021 |
| TC Renewables Holdings Limited | Financial services | 2024 |
| TCR Wind Ltd | Construction | 2019 |
| Templemoyle Plastering Ltd | Construction | 2016 |
| Terex Roofing & Guttering Ltd | Construction | 2024 |
| TES Contracts (NI) Ltd | Construction | 2014 |
| Tfleot Ltd | Professional & scientific | 2026 |
| THE Aesthetics Studio by Emma Ltd | Health & social care | 2025 |
| THE Bethany Community Trust | Construction | 2016 |
| THE Big House (Ireland) | Other services | 2008 |
| THE Broighter Co Ltd | Manufacturing | 2024 |
| THE Causeway Artisan Company Ltd | Manufacturing | 2025 |
| THE County Londonderry Agricultural Show Society Ltd | Administrative & support | 2011 |
| THE FAT FOX Cafe Ltd | Hospitality | 2024 |
| THE Fit Escape Ltd | Arts & recreation | 2025 |
| THE Mansion Block Rosses Gate Management Company Ltd | Households | 2023 |
| THE Meadows Carryduff Management Ltd | Households | 2026 |
| THE Pink Plum Ltd | Hospitality | 2025 |
| THE Point Bar Properties Limited | Real estate | 2012 |
| THE Promo Rooms Ltd | Professional & scientific | 2024 |
| THE Rock Castlerock Management Company Ltd | Households | 2022 |
| THE Service Quarter @ the Woodside Ltd | Hospitality | 2021 |
| THE Service Quarter Limited | Administrative & support | 2021 |
| THE Stables (Portstewart) Management Company Ltd | Households | 2003 |
| THE WEE Game Studio Ltd | Information & communication | 2024 |
| Thompson Connection Limited | Real estate | 2024 |
| Tierco Group Limited | Professional & scientific | 2018 |
| Tierco Ltd | Extraterritorial | 2025 |
| Tierney Associates Ltd | Health & social care | 2011 |
| Timber Factory Limited | Professional & scientific | 2019 |
| Tircreven Engineering Limited | Professional & scientific | 2023 |
| Tirmaquin Rental Ltd | Hospitality | 2009 |
| Togail Homes Limited | Construction | 2016 |
| Tomhas Ltd | Professional & scientific | 2024 |
| Tona Ireland Limited | Construction | 2015 |
| Trade Farm NI Ltd | Wholesale & retail | 2020 |
| Traditional Garden Games Limited | Wholesale & retail | 2012 |
| Trafalgar Court Mews Property Management Company Limited | Households | 2002 |
| Trix's Softplay Ltd | Arts & recreation | 2025 |
| TRS Construction Ltd | Construction | 2023 |
| Trutension Testing Ltd | Professional & scientific | 2026 |
| Turnaface Management Company Limited | Households | 2005 |
| Tyler Property Investments Limited | Real estate | 2017 |
| Ulster Consulting Limited | Professional & scientific | 2013 |
| Ulster Theatre Company Ltd | Arts & recreation | 1988 |
| Unique Leisure Inns Ltd | Hospitality | 2016 |
| Urban Catering Ltd | Hospitality | 2010 |
| V & K Potatoes Limited | Wholesale & retail | 2018 |
| V. Semple & Sons Limited | Manufacturing | 1988 |
| Valley Regional Training Centre Limited | Other services | 2014 |
| Velton Limited | Manufacturing | 2010 |
| Veram Limited | Construction | 2016 |
| Victoria Court (Waterside) Management Company Limited | Households | 2000 |
| Victoria Meadows Management Limited | Households | 2010 |
| Vineyard Road Limited | Real estate | 2020 |
| Vogue Ladies Fashions & Shoes Ltd | Wholesale & retail | 2014 |
| VSD Property Company | Administrative & support | 2012 |
| W & R Commercial Ltd | Hospitality | 2024 |
| W & R Holdings Inns Ltd | Hospitality | 2016 |
| W & R Properties Ltd | Administrative & support | 2016 |
| W Beckett Electrical Ltd | Construction | 2026 |
| W J Stevenson Ltd | Agriculture & fishing | 2015 |
| W&D Property Ltd | Real estate | 2023 |
| W&D Rentals Ltd | Real estate | 2023 |
| W&D the Corner Bar Ltd | Hospitality | 2023 |
| W&D Trinity Limited | Hospitality | 2024 |
| W&R Group Limited | Real estate | 2018 |
| W&R Hospitality Ltd | Professional & scientific | 2016 |
| W. B. Thompson & Co. Limited | Professional & scientific | 2020 |
| W. H. Nutt & SON Ltd | Wholesale & retail | 2015 |
| Walworth Demesne Limited | Hospitality | 2025 |
| Waterfoot Park Management Company Ltd | Households | 2003 |
| Watson Invest Limited | Financial services | 2024 |
| Wattstown Management Company Ltd | Households | 2021 |
| WB Hold Co Ltd | Financial services | 2026 |
| Wblrc Ltd | Construction | 2026 |
| Wd-Associate (Support) Limited | Administrative & support | 2019 |
| Webuild (IRE) Ltd | Construction | 2020 |
| Wellington Management Maghaberry Ltd | Households | 2017 |
| WFI (NI) Ltd | Hospitality | 2014 |